This invention relates to a laying device for a bridge composed of connectable bridge elements and, more particularly, to a laying device having an extendable and swivelling laying beam and a carriage movable on the laying beam including a swivable elevating platform. The bridge elements are disposed on the platform
A known laying vehicle for a bridge composed of connectable bridge elements is described in German Patent Document DE-OS 38 14 502. The laying vehicle includes a laying beam which can be moved out and swivelled, a carriage which can be moved on the laying beam, and an elevating platform on which the bridge elements are disposed. In this case, the bridge elements are moved into their intended shape by the elevating platform, are connected to the previously erected bridge elements, and are displaced on the laying beam over the obstacle. The precise details are not indicated in this case.
German Patent Document DE-OS 29 26 594 describes a bridge laying vehicle having a longitudinally displaceable bridge carrier by means of which the bridge can be displaced toward the front and toward the rear, thereby changing the axle load of the vehicle.
There is currently needed a laying device which can lay longer bridges without requiring any front-part carrying device.
The present invention meets this need by providing a laying device having a laying beam which is extendable and swivellable. A carriage is movably mounted on the laying beam and includes a swivelling elevating platform on which the connectable bridge elements are disposed. A first holding device provided on the laying beam locks previously connected bridge elements A second holding device provided on the carriage locks a next connectable bridge element to be laid wherein the carriage lifts and moves the whole constructed bridge off of the laying beam.
A laying device according to an embodiment of the present invention has an elevating platform that is swivelled with respect to the carriage around an axis in the rearward area of the platform and carriage The laying device further comprises a supporting system which is swivellable and extendable arranged on the laying beam.
In another advantageous embodiment of the present invention, the elevating platform includes a horizontally extending joint such that when the platform is lifted, its forward part is brought into a horizontal position
According to the present invention, a travelling carriage is provided which rolls on the laying beam. The travelling carriage has an elevating platform which can hold the bridge, move it forward toward the next connecting point and deposit it on the laying beam. The carriage can then connect the next bridge part. The completed parts of the bridge or the whole bridge can be lifted and moved toward the front to a depositing site. As a result of the elevating platform according to the present invention, rollers or rails are not required either on the bridge or for guiding the bridge on the laying beam.
As a result, all of the elements normally required for moving the bridge (such as rollers, rails, drives, etc.) are no longer part of the bridge but are integrated into the laying system. This has a very favorable effect on the required standing moment because the bridge may now have a lighter design.
It is an advantage of the laying device according to the present invention that it is possible to lay different types of bridges with only slight changes. Because rollers or rails for the bridge are not required, the bridges must not be specifically adapted to the laying vehicle. It is therefore possible to assemble and lay different types of bridges having larger lengths.
The laying device according to the present invention makes it possible to unfold, assemble, and lay a bridge that can be varied in its height, such as the telescopic truss bridge described in German Patent Document DE-OS 38 14 502. In this case, the substructure of the bridge is held on the carriage, and the bridge floor pieces are moved to the required height with a length measuring system by means of hydraulic cylinders of the elevating platform. The telescopic diagonal braces are pulled apart and are subsequently locked from the elevating platform.
The construction in which the carriage and the elevating platform have a common swivelling axis in their rearward area, such as a fixed hinge on the rear edges of both structural members, is particularly simple and stable. In this embodiment, the elevating platform can be swivelled with respect to the carriage by means of, for example, two hydraulic cylinders. For example, the platform can be swivelled approximately fifteen degrees (15.degree.).
In another embodiment of the invention, a supporting system, provided on the swivelling laying beam, can be swivelled and moved out with respect to the laying beam. By means of the moving-out of the long laying beam with the supporting system in the front, the standing moment can be significantly increased by the large lever arm without the requirement of increasing the weight of the vehicle because the vehicle now acts as a balance weight. Since the weight of the bridge is reduced because the normal rollers or rails on the bridge are eliminated, the standing moment is further increased, resulting in the capability of laying longer bridges
It is advantageous that the present invention generates a high standing moment of the laying device without increasing the weight of the laying device; reduces the weight of the bridge by transferring the bridge displacement devices and the bridge erecting devices from the bridge to the laying system; and allows for the laying of a forty meter bridge (such as a telescopic truss bridge) with a dead weight of approximately fourteen tons composed of four segments (equalling eight bridge elements). In this case, the bridge may be transported on one vehicle and, from that one vehicle, may be unfolded, assembled and laid to different heights. It is also possible to lay the four segments individually as shorter bridges or to lay, for example, two segments as a longer bridge and the two other segments as individual bridges.
Since, in the case of this laying device, all active elements are integrated into the laying system, the laying operation can be efficiently automated.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.